This invention relates to a new and distinct cultivar of the Saxifragaceae family. The botanical name of the plant is Hydrangea macrophylla (Thunb.) ‘True Blue’.
The new cultivar originated as a seedling from a controlled cross between the commercial variety Hydrangea macrophylla (Thunb.) ‘Blue Danube’ and the commercial variety Hydrangea macrophylla (Thunb.) ‘Blue Sky’.
The variety ‘True Blue’ has pigmented sepals, and is typically grown under soil conditions with pH conditions that produce blue pigmentation. The new variety was first noticed, because it combined the desirable growth characteristics of its parents while producing flowers with sepals that have long-lasting pigmentation. The variety ‘True Blue’ has strong stems like its parent ‘Blue Sky’ and the compactness of its parent ‘Blue Danube’. The florets of ‘True Blue’ are also glaucescent as compared to the parent ‘Blue Danube’, and the panicle of ‘True Blue’ is significantly larger than the panicle of ‘Blue Danube’.
The growth habit of ‘True Blue’ also distinguishes it from other varieties of Hydrangea that have blue sepals of which the inventor is aware. ‘True Blue’ is more compact and its stems sturdier than the blue, commercially available variety ‘Mathilda’. The pedicels of ‘True Blue’ also appear to be stronger, creating a stronger panicle than ‘Henriksberg’, another commercially available, blue variety.
The new cultivar ‘True Blue’ has been successfully asexually reproduced under controlled environmental conditions at a nursery in Half Moon Bay, Calif. under the direction of the inventor over a three year period with its distinguishing characteristics remaining stable.
‘True Blue’ is distinguished from other blue varieties of Hydrangea of which the inventor is aware by the manner in which its sepals age and change color. Sepal color of ‘True Blue’ is predominately blue at maturity. The sepals of the very young, unopened florets are R.H.S. 145 C (yellow-green group). Then, as the florets begin to age, the sepals turn purple, and then white. The characteristic that distinguishes ‘True Blue’ from all other varieties known to the inventor is that as the mature sepals age and turn purple they are highly resistant to burning and turning brown, unlike many other Hydrangeas. This makes the flowers of the plant more attractive for longer periods of time.
Asexual reproduction was first accomplished when vegetative cuttings were taken from the initially selected plant. Examination of asexually reproduced, successive generations grown in at Half Moon Bay, Calif. show that the combination of characteristics as herein disclosed for ‘True Blue’ remains firmly fixed through three generations.